Field of the Invention
The present disclosure relates to a recoding element substrate and a liquid ejection head.
Description of the Related Art
In a field of a liquid ejection apparatus represented by an ink-jet apparatus, for efficiently using generated energy as ejection energy, it is required to reduce thickness of an ejection port forming member in which ejection ports are formed. When the thickness of the ejection port forming member is reduced, however, strength of the ejection port forming member is reduced. When the liquid ejection apparatus is driven for a long time, it is concerned that a member, such as the ejection port forming member, that forms a liquid ejection head is deformed due to influence of swelling caused by absorption of liquid or influence of heat, and when the thickness is small, in particular, the deformation becomes great. Also in a case where external force is applied to the election port forming member, for example, by a wiping operation for wiping out liquid, when the strength is small, it is considered that the ejection port forming member is broken and ejection performance is deteriorated.
Japanese Patent Laid-Open No. 2013-233795 discloses a liquid ejection head having a support member that is provided between an ejection port forming member and a substrate and supports the ejection port forming member, in order to improve strength of the ejection port forming member and prevent deformation due to swelling. In the liquid ejection head, supply ports, serving as apertures of a supply passage, which penetrate the substrate in a thickness direction are provided so as to hold an energy generating element therebetween. With such a configuration, since liquid is supplied from both sides of the energy generating element, high-speed driving becomes possible, and further, election ports and the vicinity thereof are more symmetrically arranged and droplets are ejected very straight, thus achieving enhancement of recording quality. One support member is provided in each space between adjacent supply ports, and the support member is provided so that a width thereof fits to an interval between the adjacent supply ports.
However, the liquid ejection head described in Japanese Patent Laid-Open No. 2013-233795 has a problem that, when thickness of the ejection port forming member is reduced, there is a case where the ejection port forming member is deformed, stress generated at an interface between the substrate and the support member tends to be easily concentrated, and peeling of the support member tends to easily occur.